Volume 121/2 (July 2015)
Notice for subscribers:
pdf of papers published in the last 2 years are available on request to the Editorial Office.
THE PROBLEM OF SMALL FOOTPRINTS IN PALEOICHNOLOGY: REMARKS ON THE EARLY PERMIAN ICHNOTAXON ERPETOPUS CASSINISI , A LOCAL SPECIES FROM SOUTHERN ALPS (NORTHERN ITALY)
LORENZO MARCHETTI, GIUSEPPE SANTI & MARCO AVANZINI
Based on well-preserved specimens, and strictly considering the influence of extramorphological (substrate-related) factors, the use of modern techniques (computer drawings, 3D acquisitions), permitted a reliable study on footprints smaller than 20 mm. Footprints of this size were mostly considered as too small and being affected by a lot of deformation, thus preventing a substantiated analysis. Our case study focuses on the Erpetopus/Camunipes dualism. Ichnologists disagree on the value of a separation of these ichnogenera, and their discussion appears rather "philosophical" than being conducted by an accurate analysis and objective data. We restudied the holotype of Camunipes cassinisi (sp. MBS 319), together with a new specimen from Southern Alps (sp. MBG 12465) that shows five well-preserved long trackways, and compared them to selected material, including the Erpetopus willistoni holotype (sp. UGKU C-8). Results suggest a synonymy of Camunipes with Erpetopus and the new combination Erpetopus cassinisi which is distinct from E. willistoni by the following anatomical features: the pes of E. cassinisi shows higher divarication angles between digits IV-V (>50°) and I-V (>130°) and a longer and variably oriented digit V, which is long about as digit II. This has interesting paleobiogeographical consequences: E. cassinisi was probably a local ichnospecies of Erpetopus in the Southern Alps.
SELECTED SPORES AND POLLEN FROM THE PERMIAN UMM IRNA FORMATION, JORDAN, AND THEIR STRATIGRAPHIC UTILITY IN THE MIDDLE EAST AND NORTH AFRICA
MICHAEL H. STEPHENSON & JOHN H. POWELL
The Umm Irna Formation, exposed along the eastern shore of the Dead Sea, has been the focus of intense palaeobotanical study, but more recently, it has been revealed that well-preserved palynological assemblages are also present. The age of the Umm Irna Formation is such that it provides a showcase for taxa from the Guadalupian (mid Permian) to Lopingian (late Permian) which are hard to find in the carbonate-dominated successions to the southeast in the Arabian Peninsula and elsewhere in the Middle East. In this paper distinctive taxa present in the Umm Irna Formation are described and illustrated, and surveyed for their stratigraphic occurrences, to consider their suitability for biozonal indices within the Guadalupian to early Lopingian. Two appear to be promising: Protohaploxypinus uttingii Stephenson and Filatoff, 2000 and Pretricolpipollenites bharadwajii Balme, 1970. The first is distinctive in that it is relatively small, has numerous, very narrow taenaie, and a shrunken intexinal corpus; the second has three narrow distal sulci. Both taxa may have first appearance levels within thePermianabove the base of the OSPZ6 palynological Biozone, and thus may be useful in the future for further biozonation.
A NEW SAURICHTHYS (ACTINOPTERYGII) FROM THE SPATHIAN (EARLY TRIASSIC) OF CHAOHU (ANHUI PROVINCE, CHINA)
ANDREA TINTORI, JIAN-DONGHUANG, DA-YONG JIANG, ZUO-YU SUN, RYOSUKE MOTANI & GUANBAO CHEN
A new species of Saurichthys, S. majiashanensis , is described. It comes from a series of marine vertebrate-bearing beds of the upper member of the Nanlinghu Formation outcropping in the large quarry at the top of Majiashan (Majia Hill) near Chaohu (Hefei City, Anhui Province, China). Its age is Middle Spathian (Olenekian, Early Triassic). This new species deeply differs from the several pre-Spathian species of Saurichthys mainly for having only two longitudinal scale rows together with a reduced grid-like structure for the neural elements in the vertebral column. Further derived characters are in the endoskeleton of the dorsal and anal fin, where radials articulate only to anterior lepidotrichia, the posterior ones being supported by the first scale from the caudal pedicle mid-dorsal and mid-ventral rows, deeply imbedded in the body. In addition, the haemal spines of the caudal region are much enlarged and reversed, with their distal parts pointing forwards. Though the skull is lacking, postcranial characters are enough to justify the erection of a new species. This new Saurichthys species, together with other few actinopterygians, can be considered as the oldest assemblage of the Triassic Middle Fish Fauna, which bloomed probably in the early Anisian and widespread especially all over the Tethys for the Middle Triassic and at least the Carnian in the Late Triassic. This new fish assemblage, together with some of the oldest marine reptiles, is considered as the beginning of the actual Triassic recovery among marine vertebrates.
EVIDENCE FOR LADINIAN (MIDDLE TRIASSIC) PLATFORM PROGRADATION IN THE GYULAKESZI AREA, TAPOLCA BASIN, WESTERN HUNGARY: MICROFACIES ANALYSIS AND BIOSTRATIGRAPHY
ZSOLT RÓBERT NAGY, NEVENKA DJERIC, †SÁNDOR KOVÁCS, ANNA ORAVECZ-SCHEFFER, FELICITÁSZ VELLEDITS, OLGA PIROS & GÁBOR CSILLAG
A shallowing-upward carbonate sequence was studied from the outcrop at Gyulakeszi, Tapolca Basin (western Hungary), and it is interpreted as a Middle Triassic (Curionii or younger) platform progradation. Two lithostratigraphic units are distinguished. Microfacies analysis and micropaleontological investigation conducted on the red nodular, cherty limestone (Vászoly and Buchenstein formations) suggest that the lower unit was deposited during the Reitzi and the Secedensis ammonoid zones. The overlying white platform limestone (upper unit) is typical of a prograding platform and includes gravity-driven deposits at the base followed by periplatform facies deposited in shallow marine warm waters around the fair-weather wave base. The section at Gyulakeszi was unaffected by fabric-destructive dolomitization, which is uncharacteristic of similar platform facies in the Balaton Highland. Isopachous and radiaxial fibrous calcite cement found in the grainstone and boundstone facies are indicative of early lithification and diagenesis in the marine phreatic zone. “Evinospongiae”-type cement is described for the first time from the Balaton Highland and it is similar to the outer platform cements published previously from the Alps (Italy and Austria). The progradation could have advanced over the pelagic limestones as early as the Curionii zone, which is an undocumented event in the Veszprém Plateau. Similar event, however, is well known from the Western Dolomites, where aggradation was followed by intense progradation during the Gredleri and Archelaus ammonoid zones. The length of this progradation event at Gyulakeszi, however, is ambiguous since proven Ladinian (Longobardian) rocks are not exposed in the study area and were not penetrated by boreholes in the Tapolca Basin.
A NEW GENUS AND SPECIES OF THE FAMILY TRACHYPACHIDAE (COLEOPTERAN, ADEPHAGA) FROM THE UPPER LADINIAN (MIDDLE TRIASSIC)
OF MONTE SAN GIORGIO
LAURA STRADA, MATTEO MONTAGNA & ANDREA TINTORI
A new genus and species of fossil Trachypachidae Praedodromeus sangiorgiensis gen. n sp. n. (Coleoptera, Trachypachidae, Eodromeinae), with well developed asymmetrical mandibles, shorter than the head, subrectangular pronotum and slender tibiae, longer than femora, is described from the Kalkschieferzone (uppermost member of the Meride Limestone) of the Swiss side of Monte San Giorgio. Trachypachidae are terrestrial Coleoptera well represented in the Mesozoic fossil record by the extinct family Eodromeinae. Up to now, more than 33 fossil species belonging to 13 genera of Eodromeinae have been described. The new species is part of a collection of fossil insects that includes members of at least six different orders. Based on the ecology of corresponding extant taxa, this insect assemblage provides new insights on the paleoenvironment of Monte San Giorgio area during the Late Ladinian. The assemblage includes terrestrial taxa that support the presence of emerged land and taxa with long-lasting aquatic larval stage (as Plecoptera and Ephemeroptera) that confirm the presence of stable fresh water basins.
FIRST EVIDENCE FOR LATE NORIAN PROGRADATION OF JULIAN PLATFORM TOWARDS SLOVENIAN BASIN, EASTERN SOUTHERN ALPS
LUKA GALE, BOŠTJAN ROŽIČ, EVA MENCIN & TEA KOLAR-JURKOVŠEK
The Late Triassic in the Southern Alps is marked by an extensive growth of carbonate platforms. Whereas Dolomia Principale dominates the western and central sections, Dachstein Limestone dominates the eastern side of the Southern Alps on the so-called Julian Platform in what is now NW Slovenia. Younger tectonic movements greatly deformed the original configuration of the Julian Platform and its margins are consequently poorly preserved. While late Tuvalian and early Norian platform progradation has been recorded on the northern and eastern side of the platform, no such information is available for the southern edge of the platform, where it borders the deeper Slovenian Basin. Three detailed sedimentological sections from the southern slopes of the Jelovica plateau span from the top of the basinal Bača dolomite to the Slatnik Formation and the prograding slope of the Dachstein Limestone. The progradation has been dated as late Norian in age, and can be correlated to a poorly-expressed coarsening event recorded in previously known sections of the Slovenian Basin. In contrast to deeper parts of the basin, shallow water conditions were established on the Jelovica plateau by the beginning of the Rhaetian.
TAPHONOMIC ASPECTS OF THE RADIAL BACKFILL OF ASTEROSOMIDS IN OLIGO-MIOCENE TURBIDITES OF CENTRAL ITALY (NORTHERN APENNINES)
One hundred asterosomid specimens from 24 sections of several flysch facies of the Northern (Tuscan-Romagna-Umbrian) Apennines have been analysed to study their radial backfill using taphonomic characteristics. These characteristics include the stratinomic position in the bed, the shape and morphology of concave or convex tunnels, the type of subhorizontal crossing, the disposition and shape of wrinkles and cracks, and newly recognized fan-shaped, micro-debris flow deposits in the sides of tunnels induced by the radial backfilling compression causing shock in mud. Many types of preservation have been found in Halopoa ichnospecies while other preservational aspects (Asterosoma and Lennea in primis, while the Fucusopsis preservation and aspect has been included in ichnogenus Halopoa). This comparative taphonomic study enhances, for the first time in the turbidites of Apennines, the role of radial backfill as a type of deposit-feeding in deep-sea firmgrounds and softgrounds, produced by soft-bodied organisms (probably worms).
THE BRECCE DELLA RENGA FORMATION:
AGE AND SEDIMENTOLOGY OF A SYN-TECTONIC CLASTIC UNIT IN THE UPPER MIOCENE OF CENTRAL APENNINES.
INSIGHTS FROM FIELD GEOLOGY
SIMONE FABBI & MARIA GRAZIA ROSSI
In the NE Simbruini Mountains, the “Brecce della Renga Fm.” is a clastic unit documenting sedimentation controlled by late Miocene extensional tectonics.The unit has been subdivided into three lithofacies and six sublithofacies, based on the arenite/rudite/pelite ratio. Massive and coarser (up to megablock size) intervals are interpreted as rockfall deposits (likely induced by earthquakes) at the toe of steep submarine escarpments. By contrast, finer levels are interpreted as having been sedimented through avalanching and turbidity flows in more distal settings, and are partly lateral to basinal hemipelagites and siliciclastic turbidites. Pelite lenses, found at various stratigraphic levels, are the result of ponded sedimentation along the clastic margin. Calcareous nannofossils analyses have been performed for age determinations on 60 fossiliferous samples, which were collected in each sublithofacies of the “Brecce della Renga Fm.”. The unit ranges from early Tortonian (MNN8b) to early Messinian (MNN11c). The age and field geometries of the older breccias document the existence of a Tortonian extensional phase, which predated the late Messinian thrusting. A progradation of the clastic wedge can be observed in the Tortonian, while Messinian deposits show a fining upwards trend. The distribution curve of clastics over time can, given the number of synsedimentary faults mapped in the area, be put in relation with the seismicity induced by the activity along such faults, which after reaching an acme in the Tortonian gradually reached a quiescent state in the early Messinian, causing the backstepping of clastic facies.
PHYLOGENETIC SIGNATURES IN THE JUVENILE SKULL AND DENTITION OF OLDUVAI EURYGNATHOHIPPUS CORNELIANUS
RAYMOND L. BERNOR, TIPHAINE COILLOT & DOMINIK WOLF
We describe and compare a Eurgnathohippus juvenile skull, RMNH67/5665 from site BKII, Olduvai Gorge, ca. 1.2 Ma. Study of the facial morphology and cheek tooth metrical data including length versus width and protocone length versus width of the dP2, 3 and 4 support the conclusion that this juvenile skull is the species Eurygnathohippus cornelianus, and that in turn Eu. cornelianus is a member of the “Sivalhippus” Complex, which includes the following superspecific clades: Sivalhippus, Eurygnathohippus, Plesiohipparion and Proboscidipparion. Recent studies suggest that Eurygnathohippus has a particularly close phylogenetic relationship with Plesiohipparion.
PAMPATHERIIDAE (XENARTHRA, CINGULATA) FROM TARIJA VALLEY, BOLIVIA:
A TAXONOMIC UPDATE
SANTIAGO RODRIGUEZ-BUALÓ, ALFREDO EDUARDO ZURITA, FLAVIO GÓIS, ANGEL R. MIÑO-BOILINI, ESTEBAN SOIBELZON & FREDDY PAREDES-RÍOS
Pampatheriidae (Middle Miocene-late Pleistocene) constitutes an extinct clade of Cingulata widely dispersed in South America, entering in Central and North America during the Great American Biotic Interchange. In the Pleistocene of South America, two genera are recorded: Pampatherium (with three species) and Holmesina (with six species). In the Pleistocene palaeofauna of Tarija Valley (Bolivia) one of the most conspicuous recorded taxa are the Cingulata, including Pampatheriidae. Until this contribution, all the remains were classified as P. typum and Pampatherium sp. Here we present a modern taxonomic revision of the Pampatheriidae of the Tarija Valley, based on previous collected and published material together with new materials obtained from fieldwork carried out during 2011-2013. The evidence indicates that a single species of Pampatheriidae is present in the Tarija Valley ( Pampatherium humboldtii ), whereas the presence of P. typum in discarded. From a chrono-stratigraphic point of view, the biochron of this species is restricted to the late Pleistocene. This supports previous hypothesis on the age of the sediments of Tarija Valley (Tolomosa Formation).